Silibinin attenuates oxidative metabolism and cytokine production by monocytes from preeclamptic women

The Effects of Silymarin on Calcium Chloride-Induced Arrhythmia in Male Rat

Antioxidants play an important role in protecting cardiac arrhythmias. Silymarin, strong antioxidant, is effective in reducing the complications caused by arrhythmias. This study was conducted to determine the effect of silymarin on the prevention and treatment of calcium chloride-induced arrhythmia. In total, 48 male rats were randomly divided into six groups: the first control group for acute administration received intravenous injection of 0.2 mL of dimethylsulfoxide, a cosolvent, immediately after induction of arrhythmia; the second control group for chronic administration, daily gavage of dimethylsulfoxide for 2 weeks before induction of arrhythmia; acute silymarin group, 100 mg/kg intravenous, immediately after the occurrence of arrhythmia; chronic silymarin group, daily gavage of 50 mg/kg for 2 weeks before induction of arrhythmia; amiodarone standard treatment, 5 mg/kg intravenous, immediately after induction of arrhythmia; and quinidine standard treatment, 10 mg/kg intravenous, immediately after induction of arrhythmia. Calcium chloride (140 mg/kg, i.v.) was used to induce arrhythmia. Electrocardiogram was recorded and monitored by PowerLab™ system. The incidence rates of premature ventricular beat (PVB), ventricular tachycardia (VT), and ventricular fibrillation (VF) were calculated. The antiarrhythmic effect of silymarin was observed with a significant decrease in the incidence of premature ventricular beat (22.56 ± 1.04%, P < 0.001), ventricular tachycardia (34.150 ± 1.59%, P < 0.001), and ventricular fibrillation (24.31 ± 1.02%, P < 0.001) compared with the control group (100%). These effects were comparable to antiarrhythmic drugs such as quinidine (29.23% ± 1.24%, 52.23% ± 1.13%, 66.31% ± 1.81%) and amiodarone (22.91% ± .72%, 41.09% ± 1.66%, 61.59% ± 1.11%). Silymarin exerts a potent antioxidant effect, thereby mitigating the risk of VT, VF, and PVC.

Progesterone modulates TNF receptors expression by Jurkat cells cultured with plasma from pregnant women with preeclampsia

Pregnant women with preeclampsia (PE) present a shift in the immune response to an inflammatory profile. This deviation could be due to the interaction of tumor necrosis factor (TNF) with TNFR1 and TNFR2 receptors, besides the failure in modulation of inflammation regulatory mechanisms. This study evaluated the effects of progesterone on the expression of TNFR1 and TNFR2 by Jurkat cells after stimulation with plasma from PE and normotensive (NT) pregnant women. Jurkat cells were cultured with or without progesterone in a medium containing 20% (v/v) plasma from PE or NT women. The expression of TNF receptors was evaluated by flow cytometry. The concentration of soluble forms of TNF receptors and cytokines was determined in culture supernatant and plasma by ELISA. The plasma of PE women showed significantly higher concentrations of sTNFR1 and TNF and lower concentrations of sTNFR2 compared to the NT group. TNFR1 receptor expression was increased in Jurkat cells, while TNFR2 was decreased after culture with PE plasma when compared with Jurkat cells cultured with progesterone and plasma from NT women. The concentration of sTNFR1, TNF, and IL-10 in the culture supernatant of Jurkat cells was increased after culture with PE plasma, while the sTNFR2 receptor was decreased when compared to the NT group. Results demonstrate that in preeclamptic women a systemic inflammation occurs with an increase of inflammatory molecules, and progesterone may have a modulating effect on the expression of TNF receptors, shifting Jurkat cells towards an anti-inflammatory profile with greater expression of TNFR2.

Silymarin and Inflammation: Food for Thoughts

Inflammation is a vital defense mechanism, creating hostile conditions for pathogens, preventing the spread of tissue infection and repairing damaged tissues in humans and animals. However, when inflammation resolution is delayed or compromised as a result of its misregulation, the process proceeds from the acute phase to chronic inflammation, leading to the development of various chronic illnesses. It is proven that redox balance disturbances and oxidative stress are among major factors inducing NF-κB and leading to over-inflammation. Therefore, the anti-inflammatory properties of various natural antioxidants have been widely tested in various in vitro and in vivo systems. Accumulating evidence indicates that silymarin (SM) and its main constituent silibinin/silybin (SB) have great potential as an anti-inflammation agent. The main anti-inflammatory mechanism of SM/SB action is attributed to the inhibition of TLR4/NF-κB-mediated signaling pathways and the downregulated expression of pro-inflammatory mediators, including TNF-α, IL-1β, IL-6, IL-12, IL-23, CCL4, CXCL10, etc. Of note, in the same model systems, SM/SB was able to upregulate anti-inflammatory cytokines (IL-4, IL-10, IL-13, TGF-β, etc.) and lipid mediators involved in the resolution of inflammation. The inflammatory properties of SM/SB were clearly demonstrated in model systems based on immune (macrophages and monocytes) and non-immune (epithelial, skin, bone, connective tissue and cancer) cells. At the same time, the anti-inflammatory action of SM/SB was confirmed in a number of in vivo models, including toxicity models, nonalcoholic fatty liver disease, ischemia/reperfusion models, stress-induced injuries, ageing and exercising models, wound healing and many other relevant model systems. It seems likely that the anti-inflammatory activities of SM/SB are key elements on the health-promoting properties of these phytochemicals.

Inhibition of Phagocytosis by Silibinin in Mouse Macrophages

This study investigated the effects of silibinin, derived from milk thistle (Silybum marianum), on lipopolysaccharide (LPS)-induced morphological changes in mouse macrophages. Silibinin was treated at various doses and time points to assess its effects on macrophage activation, including morphological changes and phagocytosis. Silibinin effectively inhibited LPS-induced pseudopodia formation and size increase, while unstimulated cells remained round. Silibinin's impact on phagocytosis was dose- and time-dependent, showing a decrease. We explored its mechanism of action on kinases using a MAPK array. Among the three MAPK family members tested, silibinin had a limited effect on JNK and p38 but significantly inhibited ERK1/2 and related RSK1/2. Silibinin also inhibited MKK6, AKT3, MSK2, p70S6K, and GSK-3β. These findings highlight silibinin's potent inhibitory effects on phagocytosis and morphological changes in macrophages. We suggest its potential as an anti-inflammatory agent due to its ability to target key inflammatory pathways involving ERK1/2 and related kinases. Overall, this study demonstrates the promising therapeutic properties of silibinin in modulating macrophage function and inflammation.

Inflammasomes in human reproductive diseases

Inflammasomes are multi-protein complexes localized within immune and non-immune cells that induce caspase activation, proinflammatory cytokine secretion, and ultimately pyroptosis-a type of cell death. Inflammasomes are involved in a variety of human diseases, especially acute or chronic inflammatory diseases. In this review, we focused on the strong correlation between the NLRP3 inflammasome and various reproductive diseases, including ovarian aging or premature ovarian insufficiency, PCOS, endometriosis, recurrent spontaneous abortion, preterm labor, pre-eclampsia, and male subfertility, as well as the multifaceted role of NLRP3 in the pathogenesis and treatment of these diseases. In addition, we provide an overview of the structure and amplification of inflammasomes. This comprehensive review demonstrates the vital role of NLRP3 inflammasome activation in human reproductive diseases together with the underlying mechanisms, offers new insights for mechanistic studies of reproduction, and provides promising possibilities for the development of drugs targeting the NLRP3 inflammasome for the treatment of reproductive disorders in the future.

Pre-Eclampsia: From Etiology and Molecular Mechanisms to Clinical Tools-A Review of the Literature

Pre-eclampsia is a severe pregnancy-related complication that manifests as a syndrome with multisystem involvement and damage. It has significantly grown in frequency during the past 30 years and could be considered as one of the major causes of maternal and fetal morbidity and mortality. However, the specific etiology and molecular mechanisms of pre-eclampsia are still poorly known and could have a variety of causes, such as altered angiogenesis, inflammations, maternal infections, obesity, metabolic disorders, gestational diabetes, and autoimmune diseases. Perhaps the most promising area under investigation is the imbalance of maternal angiogenic factors and its effects on vascular function, though studies in placental oxidative stress and maternal immune response have demonstrated intriguing findings. However, to determine the relative importance of each cause and the impact of actions aiming to significantly reduce the incidence of this illness, more research is needed. Moreover, it is necessary to better understand the etiologies of each subtype of pre-eclampsia as well as the pathophysiology of other major obstetrical syndromes to identify a clinical tool able to recognize patients at risk of pre-eclampsia early.

Common pregnancy complications and polyphenols intake: an overview

During pregnancy, the body undergoes a great amount of changes in order to support a healthy developing fetus. In this context, maternal dietary supplementation is widely encouraged to provide adequate nutrition for the newborn. In the past few years, studies have emerged highlighting the benefits of polyphenols intake during pregnancy. Indeed, despite differences among reports, such as experimental model, polyphenol employed, dosage and regimen of administration, there is no doubt that the ingestion of these molecules has a protective effect in relation to three pregnancy-associated diseases or conditions: preeclampsia, gestational diabetes and fetal growth restriction. In this review, we describe the effects of different polyphenols and polyphenol-rich extracts or juices on the main outcomes of these common pregnancy-associated complications, obtained in human, animal and in vitro studies. Therefore, this work provides a critical analysis of the literature, and a summary of evidences, from which future research using polyphenols can be designed and evaluated.

Pre-pregnancy check-up of maternal vascular status and associated phenotype is crucial for the health of mother and offspring

Abstract

Cardiovascular disease remains the leading cause of disease burden globally with far-reaching consequences including enormous socio-economic burden to healthcare and society at large. Cardiovascular health is decisive for reproductive function, healthy pregnancy and postpartum. During pregnancy, maternal cardiovascular system is exposed to highly increased haemodynamic stress that significantly impacts health status of the mother and offspring. Resulting from sub-optimal maternal health conditions overlooked in pre-pregnancy time, progressive abnormalities can be expected during pregnancy and postpartum. Contextually, there are two main concepts to follow in the framework of predictive, preventive and personalised medicine, namely to develop:

1. advanced screening of sub-optimal health conditions in young populations to predict and prevent individual health risks prior to planned pregnancies

2. in-depth companion diagnostics during pregnancy to predict and prevent long-lasting postpartum health risks of the mother and offspring.

Data collected in the current study demonstrate group-specific complications to health of the mother and offspring and clinical relevance of the related phenotyping in pre-pregnant mothers. Diagnostic approach proposed in this study revealed its great clinical utility demonstrating important synergies between cardiovascular maladaptation and connective tissue dysfunction. Co-diagnosed pre-pregnancy low BMI of the mother, connective tissue dysfunction, increased stiffness of peripheral vessels and decreased blood pressure are considered a highly specific maternal phenotype useful for innovative screening programmes in young populations to predict and prevent severe risks to health of the mother and offspring. This crucial discovery brings together systemic effects characteristic, for example, for individuals with Flammer syndrome predisposed to the phenotype-specific primary vascular dysregulation, pregnancy-associated risks, normal tension glaucoma, ischemic stroke at young age, impaired wound healing and associated disorders. Proposed maternal phenotyping is crucial to predict and effectively protect both the mother and offspring against health-to-disease transition. Pre-pregnancy check-up focused on sub-optimal health and utilising here described phenotypes is pivotal for advanced health policy.

Plain English abstract

Cardiovascular health is decisive for reproductive function and healthy pregnancy. During pregnancy, maternal cardiovascular system may demonstrate health-to-disease transition relevant for the affected mother and offspring. Overlooked in pre-pregnancy time, progressive abnormalities can be expected during pregnancy and lifelong. Here we co-diagnosed maternal pre-pregnancy low bodyweight with systemic effects which may increase risks of pregnancy, eye and heart disorders and ischemic stroke at young age, amongst others. Innovative screening  programmes focused on sub-optimal health in young populations to predict and to mitigate individual health risks prior to pregnancy is an essential innovation for health policy proposed.

Silibinin ameliorates abrin induced hepatotoxicity by attenuating oxidative stress, inflammation and inhibiting Fas pathway

Abrin is a toxin from the seeds of Abrus precatorius. Abrin is considerably more toxic than ricin and a potent bio-warfare agent. The mechanism of abrin induced hepatotoxicity remains unclear. Silibinin has antioxidant, anti-inflammatory and hepatoprotective activities. But, its therapeutic potential in abrin toxicity is unknown. In view of these facts, the purpose of this study was to delineate the mechanisms and ameliorative role of silibinin against abrin induced hepatotoxicity. Parameters related to liver functions, oxidative stress, inflammation, Fas pathway and histopathology were evaluated in the liver of BALB/c mice after abrin exposure. Abrin intoxication resulted in hepatotoxicity, oxidative stress, inflammation, altered histopathology and increased Fas pathway signaling. Silibinin improves survival of abrin-exposed mice by decreasing serum liver enzymes and reinstating the antioxidant capacity. Silibinin also inhibits abrin-induced inflammation and Fas pathway. Present study for the first time demonstrates the hepatoprotective potential of silibinin against abrin toxicity.

Modulatory effect of two regimens of magnesium sulfate on the systemic inflammatory response in pregnant women with imminent eclampsia

OBJECTIVE

This study compared the modulatory effect of two intravenous magnesium sulfate (MgSO₄) regimens on the systemic inflammatory response in pregnant women diagnosed with imminent eclampsia.

STUDY DESIGN

In a single-blind cross-sectional study, 33 women were allocated according to the Zuspan (n = 16) and Sibai (n = 17) MgSO₄ regimens, and treated for 24 h. Blood samples were collected pre-administration of the loading dose, at 24 h of the maintenance dose of MgSO₄, and at 48 h, when patients were without treatment. Plasma was used to determine interleukin (IL)-1 beta (IL-1β), IL-6, IL-10, tumor necrosis factor-alpha (TNF-α), heat shock protein (Hsp70), and heme oxygenase-1 (HO-1) by ELISA.

RESULTS

The treatment with the Zuspan's regimen didn't change plasma concentrations of TNF-α, IL-10, and Hsp70 in the three-time points studied. However, it decreased IL-1β at 24 h and 48 h and IL-6 at 48 h, and increased HO-1 concentration at 48 h. On the other hand, compared to the pre-treatment period, Sibai's regimen induced a significant decrease in TNF-α, IL-1β, IL-6, and Hsp70, while increased HO-1 levels both at 24 h and 48 h and, IL-10 concentration at 48 h.

CONCLUSIONS

Sibai's regimen determined an early and efficient immunoregulatory effect on systemic inflammatory response in preeclampsia, suggesting that the maintenance dose of two grams of MgSO₄ was better than one gram in the treatment of imminent eclampsia.

DAMPs are able to skew CD4+ T cell subsets and increase the inflammatory profile in pregnant women with preeclampsia

Preeclampsia (PE) is characterized by abnormal activation of the immune system. The intense systemic inflammatory reaction, could be related to the presence of molecules released after cell stress or death, that are capable of inducing inflammation and are known as damage-associated molecular patterns (DAMP). This study evaluated the profile of T cells through the analysis of transcription factors and the cytokines produced after culture with or without DAMPs: heat shock protein 70 (Hsp70), hyaluronan (HA) and monosodium urate (MSU). Twenty pregnant women with PE, 20 normotensive (NT) pregnant women and 20 non-pregnant (NP) women were studied. The results showed polarization toward Th1/Th17 and a decrease in Th2/Treg profiles in preeclamptic women associated with elevated levels of TNF, IFN-γ, and IL-17A and diminished levels of TGF-β1 and IL-10 when compared to the normotensive group. In addition, preeclamptic women had a higher percentage of cells co-expressing T-bet/GATA-3 and T-bet/RORγt and fewer T-bet/FoxP3 cells when compared to normotensive group. MSU induced an increase in IFN-γ and IL-22 in all studied groups. MSU, HA, and Hsp70 induced significant higher production of TNF in the PE and NP groups. The PE group showed elevated levels of TGF-β1 after incubation with MSU, HA, and Hsp70, whereas HA and Hsp70 decreased TGF-β1 production in NT group. The results suggest that these alarmins may play a role in the activation of innate and adaptive immune systems by skewing CD4 + T cells and increasing the release of inflammatory cytokines, thereby contributing to the pathogenesis of this important syndrome.

Protective effect of Fisetin on the lipopolysaccharide-induced preeclampsia-like rats

OBJECTIVE

This article is aimed to investigate the function and underlying action mechanism of Fisetin in LPS-induced PE rats.

METHODS

LPS-induced PE-like rat model was established to explore the effects of Fisetin on PE in vivo.

RESULTS

Fisetin reduced hypertension, proteinuria, TNF-α, IL-6, IL-1β, MDA, and sFlt-1/PlGF ratio, but elevated the placental, fetal weight, GSH and SOD in PE rats. Moreover, Fisetin suppressed TLR4/NF-κB pathway, as well as promoting Nrf2/HO-1 pathway in placental tissues of PE rats.

CONCLUSIONS

Fisetin exerted protective role and modulated the activation of TLR4/NF-κB and Nrf2/HO-1 pathways in PE-like rat models.

Association between Adverse Maternal Clinical Outcomes and Imbalance of Cytokines and Angiogenic Factors in Preterm Preeclampsia

OBJECTIVE

 Preeclampsia (PE) is a pregnancy-specific syndrome characterized by abnormal levels of cytokines and angiogenic factors, playing a role in the disease development. The present study evaluated whether immunological markers are associated with the gestational age and with the disease severity in preeclamptic women.

METHODS

 Ninety-five women who developed PE were stratified for gestational age as preterm PE (< 37 weeks) and term PE (≥ 37 weeks of gestation) and compared for disease severity as well as plasma concentration of angiogenic factors and cytokines. The concentrations of placental growth factor (PlGF), vascular endothelial growth factor (VEGF), Fms-like soluble tyrosine kinase (sFlt-1) and soluble endoglin (sEng), as well as the cytokines, tumor necrosis factor-α (TNF-α) and interleukin 10 (IL-10), were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

 The comparison between preeclamptic groups showed a higher percentage of severe cases in preterm PE (82.1%) than in term PE (35.9%). Similarly, the concentrations of TNF-α, sFlt-1, and sEng, as well as TNF-α/IL-10 and sFlt-1/PlGF ratios were significantly higher in the preterm PE group. In contrast, concentrations of PlGF, VEGF, and IL-10 were significantly lower in women with preterm PE. Negative correlations between TNF-α and IL-10 (r = 0.5232) and between PlGF and sFlt1 (r = -0.4158) were detected in the preterm PE.

CONCLUSION

 In pregnant women with preterm PE, there is an imbalance between immunological markers, with the predominance of anti-angiogenic factors and TNF-α, associated with adverse maternal clinical outcomes.

Plant Phenolics and Extracts in Animal Models of Preeclampsia and Clinical Trials-Review of Perspectives for Novel Therapies

The current health requirements set the direction in pharmacological research, especially as regards diseases that require improvement of existing therapeutic regimens. Such diseases include preeclampsia, which is a hypertensive disorder of pregnancy during which there occurs progressive increasing activation of the immune system through elevation of pro-inflammatory cytokines and antiangiogenic factors, which is dangerous for the mother and fetus. A promising field of research for new drugs to treat this disease is the study of natural phenolic compounds of plant origin and herbal extracts, which are complex matrices of chemical compounds with broad biological activities. Many plant substances with anti‑inflammatory and anti‑hypertensive properties are known, but studies in animal models of preeclampsia and clinical trials concerning this disease constitute a new and developing research trend of significant medical importance. The aim of our research review was to identify and analyze the results of already available studies on baicalin, curcumin, epigallocatechin gallate, punicalagin, quercetin, resveratrol, salvianolic acid A (danshensu), silibinin, and vitexin, as well as plant extracts from Brassica oleracea L., Euterpe oleracea Mart., Moringa oleifera Lam., Punica granatum L., Silybum marianum (L.) Gaertner, Thymus schimperi Ronniger, Uncaria rhynchophylla (Miq.) Miq. ex Havil., and Vitis vinifera L., which are potential and promising candidates for further research and for potential new therapies.

Monocytes from preeclamptic women previously treated with silibinin attenuate oxidative stress in human endothelial cells

Objective: To investigate whether the supernatant from monocytes of preeclamptic and normotensive pregnant women, cultured in vitro with silibinin, can modulate oxidative stress in HUVEC.Methods: Concentrations of IL-1β, IL-10, and TNF-α in monocyte culture supernatants were determined by ELISA. HUVEC and their supernatant cultures were employed for determination of NO, nitrite and nitrate, lipid peroxidation, and hemeoxygenase-1 (HO-1).Results: HUVEC treatment with supernatant of preeclamptic monocytes cultured with silibinin produced increased levels of nitrite, reduced lipid peroxidation, and increased HO-1.Conclusion: Supernatant of monocytes from preeclamptic women induce oxidative stress in HUVEC which can be reduced by silibinin treatment.Abbreviations: DAF-FM^TM, Diaminofluorescein-FM; EDTA, Ethylenediaminetetraacetic acid; HO-1, heme oxygenase-1; HPLC, high-performance liquid chromatography; HUVEC, human umbilical vein endothelial cell; MDA, malondialdehyde; NO, nitric oxide; NT, normotensive; PE, preeclampsia; ROS, reactive oxygen species; Sb, silibinin.

Progesterone and vitamin D downregulate the activation of the NLRP1/NLRP3 inflammasomes and TLR4-MyD88-NF-κB pathway in monocytes from pregnant women with preeclampsia

This study evaluated the in vitro modulatory effect of progesterone (PG) and vitamin D (VD) on NLRP1/NLRP3 inflammasomes and TLR4/NF-κB pathway in monocytes from pregnant women with preeclampsia (PE). Monocytes from 20 preeclamptic and 20 normotensive (NT) pregnant women, and THP-1 cells were cultured with/without hyaluronan (HA), PG, or VD to determine gene and protein expression of TLR4 receptor, phosphorylated NF-κB, IκBα, TLR4, MYD88, NF-κB, NLRP1, NLRP3, caspase-1, IL-1β, IL-18, TNF-α, and IL-10. Higher endogenous activation of inflammatory genes and higher protein expression of TLR4 and NF-κB was detected in monocytes of PE group and decreased after PG or VD treatment. Monocyte from PE stimulated with HA increased while treatment with PG or VD decreased the expression of genes and proteins related to the inflammasomes. THP-1 cells showed a similar immune response profile as monocytes from PE. These results demonstrate that PG and VD play an immunomodulatory role in monocyte activation.

Silibinin ameliorats H2O2-induced cell apoptosis and oxidative stress response by activating Nrf2 signaling in trophoblast cells

Preeclampsia is a pregnancy-specific syndrome and is one of the major causes of maternal mortality around the world. Cell apoptosis and oxidative stress are involved in development of preeclampsia. Silibinin has been known with anti-inflammatory, anti-oxidative and anti-tumor roles. In this study, hydrogen peroxide (H₂O₂) administration induced apoptosis in HTR-8/SVneo trophoblast cells, evidenced by decreased level of Bcl-2 and increased levels of Bax and cleaved caspase-3. Western blot and JC-1 staining revealed that H₂O₂ led to decline of mitochondrial membrane potential (Δψm) and release of cytochrome C from mitochondria to cytoplasm. H₂O₂ also resulted in reactive oxygen species production and oxidative stress response, evidenced by elevated levels of malondialdehyde, and reduced activity of superoxide dismutase and glutathione peroxidase. Silibinin suppressed H₂O₂-induced apoptosis, decrease of Δψm and oxidative stress response. In addition, immunofluorescent staining and electrophoretic mobility shift assay demonstrated that H₂O₂ enhanced expression and nuclear translocation of nuclear factor-erythroid 2-like 2 (Nrf2), and the expression levels of heme oxygenases-1 and quinone oxidoreductase 1 were increased, suggesting the activation of Nrf2 signaling. The activity of Nrf2 signaling was further promoted by silibinin administration. Interestingly, the effect of silibinin on apoptosis and oxidative stress was abolished by interference RNA of Nrf2. In conclusion, we demonstrated that silibinin ameliorated H₂O₂-induced apoptosis and oxidative stress response by activating Nrf2 signaling in trophoblast cells. These findings may provide novel insights for treatment of preeclampsia.

Preeclamptic Women Have Decreased Circulating IL-10 (Interleukin-10) Values at the Time of Preeclampsia Diagnosis: Systematic Review and Meta-Analysis

A key immunomodulatory cytokine, IL-10 (interleukin-10), has been shown to be dysregulated in preeclampsia, a pregnancy-specific hypertensive disorder, further characterized by multi-system involvement. However, studies have reported inconsistent findings about circulating IL-10 levels in preeclamptic versus normotensive pregnancies. The aim of the present systematic review and meta-analysis was to assess circulating IL-10 levels in preeclamptic and normotensive pregnancies at 2 time points: before, and at the time of preeclampsia diagnosis. PubMED, EMBASE, and Web of Science databases were searched to include all published studies examining circulating IL-10 levels in preeclamptic and normotensive pregnancies. Differences in IL-10 levels were evaluated by standardized mean differences. Of 876 abstracts screened, 56 studies were included in the meta-analysis. Circulating IL-10 levels were not different before the time of active disease (standardized mean differences, -0.01 [95% CI, -0.11 to 0.08]; P=0.76). At the time of active disease, women with preeclampsia (n=1599) had significantly lower IL-10 levels compared with normotensive controls (n=1998; standardized mean differences, -0.79 [95% CI, -1.22 to -0.35]; P=0.0004). IL-10 levels were lower in both early/severe and late/mild forms of preeclampsia. Subgroup analysis revealed that IL-10 measurement methodology (ELISA or multiplex bead array) and the sample type (plasma or serum) significantly influenced the observed differences, with the use of sera paired with ELISA technology providing the best distinction in IL-10 levels between preeclamptic and normotensive pregnancies. These findings support the role of decreased IL-10 levels in the pathophysiology of preeclampsia. Future studies should address the therapeutic potential of IL-10 in preeclampsia.

Silibinin induces in vitro M2-like phenotype polarization in monocytes from preeclamptic women

Preeclampsia (PE) is a pregnancy-specific syndrome featuring intense activation of circulating monocytes and an imbalance between pro- and anti-inflammatory cytokines. The present study evaluated the immunomodulatory effect of silibinin (Sb) on the expression of surface markers and the nuclear transcription factor NF-κB signalling pathway of monocytes from preeclamptic women. Monocytes were cultured with or without Sb, and the mean fluorescence intensity of the surface molecules TLR4, CD64, and CD163 as well as the intracellular transcription factors IκB-α and NF-κBp65 was analysed by flow cytometry. The concentration of cytokines in the monocyte culture supernatant was determined by cytometric bead array and ELISA immunoassay. The results showed that the in vitro treatment of monocytes from preeclamptic women with Sb downregulated the endogenous activation of NF-κB and the expression of surface receptors TLR4 and CD64, and reduced the synthesis of the pro-inflammatory cytokines interleukin 1 (IL-1β), IL-6, IL-8, IL-12p70, IL-23, and tumour necrosis factor alpha (TNF-α) compared with cultures not treated with Sb. The presence of this flavonoid in monocyte cultures increased the expression of CD163 and IκBα and the release of IL-10 and transforming growth factor beta (TGF-β) in the culture supernatants, polarising these cells from the M1-like profile to the M2-like profile. The anti-inflammatory activity of Sb on the NF-κB activation pathway and induction of cell polarisation to the M2 profile was confirmed by an in vitro assay using monocytes from healthy, non-pregnant women. Treatment of monocytes from preeclamptic women with Sb polarises the cells to the M2-like phenotype, suggesting that this flavonoid has an immunomodulatory effect on the sterile inflammation characteristic of PE.

Increased TLR4 pathway activation and cytokine imbalance led to lipopolysaccharide tolerance in monocytes from preeclamptic women

Preeclampsia (PE) is a pregnancy syndrome characterized by a systemic inflammatory response, and endogenous activation of monocytes. This study aimed to determine whether the activation of monocytes from preeclamptic women might interfere with the response to lipopolysaccharide (LPS)-in vitro stimulation. Fifty-two preeclamptic women and 32 normotensive (NT) pregnant women were included. Monocytes from peripheral blood were cultured with or without LPS. TLR4 expression was analyzed by flow cytometry, NF-κB activity was determined in nuclear extracts and cytokines production was evaluated by ELISA. Endogenous TLR4 ligands such as Hyaluronan, HMGB1 and Hsp70 were determined in plasma. The endogenous TLR4 expression and activation of NF-κB were statistically higher in monocytes from women with PE compared to NT group. Early-onset PE showed higher TLR4 expression compared to late-onset PE. Plasma levels of Hyaluronan, HMGB1, and Hsp70, as well as endogenous production of inflammatory cytokines, were elevated whilst lower production of IL-10 was observed in the PE group. After culture with LPS, monocytes presented lower NF-κB activation, TNF-α and IL-12 production in PE groups than in the NT group. The study demonstrates endogenous activation of monocytes from preeclamptic women, accompanied by higher expression of TLR4, NF-κB activation and elevated production of pro-inflammatory cytokines. The higher plasma levels of the TLR4 ligands hyaluronan, HMGB1 and hsp70, as well as the high concentration of TNF-α endogenously produced by monocytes, could induce the LPS tolerance phenomenon in these cells. These results suggest that monocytes play an important role in the maternal excessive systemic inflammatory response in PE.

Experimental drugs for the inhibition of preterm labor

INTRODUCTION

Preterm birth is the leading cause of neonatal morbidity and mortality globally and poses a substantial economic burden. Consequently, there is a need for the identification of therapeutic targets and novel experimental drugs for the inhibition of preterm labor to improve neonatal outcomes.

AREAS COVERED

The authors review the pathophysiology of labor and the inflammatory pathways underpinning it. The interruption of these pathways forms the basis of therapeutic targets to inhibit preterm labor. Current drugs available for the treatment of preterm labor are reviewed, followed by experimental drugs including toll-like receptor 4 (TLR-4) antagonists, cytokine suppressive anti-inflammatory drugs (CSAIDs), N-acetyl cysteine (NAC), Sulfasalazine (SSZ), tumor necrosis factor-alpha (TNF-α) antagonists, interleukin-1 receptor (IL-1) inhibitors, omega-3 polyunsaturated fatty acids and lipid metabolites, and the polyphenols.

EXPERT OPINION

A number of new therapeutic strategies for the prevention of preterm labor are being investigated. These have the potential to improve neurodevelopmental outcomes and survival in babies born preterm, reducing the economic and healthcare costs of caring for the complex needs of these children in the immediate and long term. It is likely that over the next decade there will be a new treatment option that targets the pathological inflammatory processes involved in preterm labor.

Inflammasomes-A Molecular Link for Altered Immunoregulation and Inflammation Mediated Vascular Dysfunction in Preeclampsia

Preeclampsia (PE) is a pregnancy-specific multisystem disorder and is associated with maladaptation of the maternal cardiovascular system and abnormal placentation. One of the important characteristics in the pathophysiology of PE is a dysfunction of the placenta. Placental insufficiency is associated with poor trophoblast uterine invasion and impaired transformation of the uterine spiral arterioles to high capacity and low impedance vessels and/or abnormalities in the development of chorionic villi. Significant progress in identifying potential molecular targets in the pathophysiology of PE is underway. The human placenta is immunologically functional with the trophoblast able to generate specific and diverse innate immune-like responses through their expression of multimeric self-assembling protein complexes, termed inflammasomes. However, the type of response is highly dependent upon the stimuli, the receptor(s) expressed and activated, the downstream signaling pathways involved, and the timing of gestation. Recent findings highlight that inflammasomes can act as a molecular link for several components at the syncytiotrophoblast surface and also in maternal blood thereby directly influencing each other. Thus, the inflammasome molecular platform can promote adverse inflammatory effects when chronically activated. This review highlights current knowledge in placental inflammasome expression and activity in PE-affected pregnancies, and consequently, vascular dysfunction in PE that must be addressed as an interdependent interactive process.

Silymarin-albumin nanoplex: Preparation and its potential application as an antioxidant in nervous system in vitro and in vivo

In this study, we formulated silymarin-HSA nanoplex and assayed its ability to reduce LPS-induced toxicity in vitro and in vivo. Silymarin molecules were encapsulated into HSA nanoplex and the loading efficiency and characterization of fabricated nanoplex were performed by using HPLC, TEM, SEM, DLS, FTIR analysis, and theoretical studies. Afterwards, their protective effect against LPS (20 µg/ml) -induced toxicity in SH-SY5Y cells was investigated by MTT, ROS, and apoptosis assays. For in vivo experiments, rats were pre-treated with either silymarin or silymarin -HSA nanoplex (200 mg/kg) orally for 3 days and at third day received LPS by IP at a dose of 0.5 mg/kg, 150 min before scarification followed by SOD and CAT activity assay. The formulation of silymarin-HSA nanoplex showed a spherical shape with an average diameter between 50 nm and 150 nm, hydrodynamic radius of 188.3 nm, zeta potential of -26.6 mV, and a drug loading of 97.3%. In LPS-treated cells, pretreatments with silymarin-HSA noncomplex recovered the cell viability and decreased the ROS level and corresponding apoptosis more significantly than free silymarin. In rats, it was also depicted that, silymarin-HSA noncomplex can increase the SOD and CAT activity in brain tissue at LPS-triggered oxidative stress model more significantly than the free counterpart. Therefore, nanoformulation of silymarin improved its capability to reduce LPS-induced oxidative stress by restoring cell viability and elevation of SOD and CAT activity in vitro and in vivo, respectively. In conclusion, formulation of silymarin may hold a great promise in the development of antioxidant agents.

A significant therapeutic effect of silymarin administered alone, or in combination with chemotherapy, in experimental pulmonary tuberculosis caused by drug-sensitive or drug-resistant strains: In vitro and in vivo studies

For many years, tuberculosis (TB) has been a major public health problem worldwide. Advances for treatment and eradication have been very limited. Silymarin (Sm) is a natural product with antioxidant and hepatoprotective activities that has been proposed as a complementary medicine to reduce the liver injury produced by the conventional anti-TB chemotherapy. Sm also has immunoregulatory and microbicide properties. In this study, we determined the effect of Sm on the growth control of mycobacteria. In vitro studies showed that Sm and Silibinin (the principal active compound of Sm) have microbicidal activity against drug-sensitive and multidrug-resistant (MDR) mycobacteria, induce the production of protective cytokines from infected macrophages, and improve the growth control of mycobacteria (p ≤ 0.0001). Studies in vivo using a model of progressive pulmonary TB in BALB/c mice infected with drug-sensitive or MDR mycobacteria have shown that Sm induces significant expression of Th-1 cytokines such as IFN-γ and IL-12 as well as TNFα, which produce significant therapeutic activity when administered alone and apparently have a synergistic effect with chemotherapy. These results suggest that Sm has a bactericidal effect and can contribute to the control and establishment of a TH1 protective immune response against mycobacterial infection. Thus, it seems that this flavonoid has a promising potential as adjuvant therapy in the treatment of TB.

Silibinin Downregulates the NF-κB Pathway and NLRP1/NLRP3 Inflammasomes in Monocytes from Pregnant Women with Preeclampsia

Preeclampsia (PE) is a human pregnancy-specific syndrome with abnormal activation of cells from the innate immune system. The present study evaluated whether silibinin (SB) treatment of monocytes from preeclamptic women could modulate NLRP1 and NLRP3 inflammasomes as well as TLR4/NF-κB pathway activation. Peripheral blood monocytes from 20 preeclamptic and 20 normotensive (NT) pregnant women, as well as the THP-1 cell line, were cultured with or without monosodium urate (MSU) or SB. NLRP1, NLRP3, Caspase-1, TLR4, MyD88, NF-κB, IL-1β, IL-18, TNF-α and IL-10 gene expression by monocytes was analysed by quantitative real-time polymerase chain reaction (qPCR), while inflammatory cytokine production and p65NF-κB activity were determined by enzyme-linked immunosorbent assays (ELISAs). TLR4/MyD88/NF-κB and NLRP1/NLRP3 inflammasomes pathways in THP-1 cells were evaluated by flow cytometry and western blot respectively. Compared with NT women, monocytes from preeclamptic women showed The Ethics Committee of the Botucatu Medical School approved the study (protocol number 2.333.216)higher endogenous activation of NLRP1/NLRP3 inflammasomes and the TLR4/NF-κB pathway as well as higher gene and protein expression of IL-1β, IL-18 and TNF-α, and lower expression of IL-10. Monocyte stimulation with MSU increased inflammation-related genes as well as NF-κB activity. In vitro, SB treatment of monocytes from preeclamptic women reduced the basal activation of these cells by decreasing NLRP1/NLRP3 inflammasomes and p65NF-κB activity. THP-1 cells exhibited a similar immunological response profile to monocytes from preeclamptic women when cultured with or without MSU or SB. These results suggest uric acid participates in the systemic inflammatory response characteristic of preeclampsia and that in vitro SB treatment can modulate the sterile inflammation established in monocytes from preeclamptic women.

Contribution of regulatory T cells to immune tolerance and association of microRNA‑210 and Foxp3 in preeclampsia

Increasing evidence suggests that an exaggerated maternal systemic inflammatofrery response may play a central role in the pathogenesis of preeclampsia (PE). Considering the growing evidence on microRNAs (miRNAs) and tissue‑specific regulators of gene expression, we investigated the potential association of miR‑210 and forkhead box p3 (Foxp3) in preeclamptic patients. Serum levels of the cytokines interleukin (IL)‑6, IL‑10, IL‑17, and transforming grown factor‑β1 were detected with ELISA. Reverse‑transcription‑quantitative polymerase chain reaction was performed to detect mRNA expression for maternal placenta retinoic acid‑related orphan receptor C, Foxp3 and miRNA (miR)‑210. Foxp3 protein expression was evaluated by western blot analysis. Serum levels of cytokines IL‑10 were significantly lower in preeclamptic patients than in normal pregnant women. mRNA expression of Foxp3 was significantly lower in placenta of PE. mRNA expression of miR‑210 was significantly increased in PE. Results of western blot analysis indicated that Foxp3 protein expression was lower in PE than in normal pregnant women. Our data suggest that PE manifests as a decreased number of regulatory T cells (Tregs), which regulate maternal tolerance of the fetus. In placenta from women with PE, compared with normal pregnant women, mRNA expression of Foxp3 was significantly decreased, and expression of miR‑210 was significantly increased.

The Role of Interleukin-10 in the Pathophysiology of Preeclampsia

PURPOSE OF REVIEW

The pathophysiology of preeclampsia is complex and not entirely understood. A key feature in preeclampsia development is an immunological imbalance that shifts the maternal immune response from one of tolerance towards one promoting chronic inflammation and endothelial dysfunction. As a key regulator of immunity, IL-10 not only has immunomodulatory activity, but also directly benefits vasculature and promotes successful cellular interactions at the maternal-fetal interface. Here we focus on the mechanisms by which the dysregulation of IL-10 may contribute to the pathophysiology of preeclampsia.

RECENT FINDINGS

Dysregulation of IL-10 has been demonstrated in various animal models of preeclampsia. Decreased IL-10 production in both placenta and peripheral blood mononuclear cells has been reported in human studies, but with inconsistent results. The significance of IL-10 in preeclampsia has shifted from a key biomarker to one with therapeutic potential. As such, a better understanding of the role of this cytokine in the pathophysiology of preeclampsia is of paramount importance.

Induction of systemic inflammation by hyaluronan and hsp70 in women with pre-eclampsia

Pre-eclampsia (PE) is a human pregnancy syndrome with abnormal activation of the innate immune response. The study evaluated the involvement of molecular structures called damage-associated molecular patterns (DAMPs), such as hyaluronan (HA) and heat shock proteins (Hsp) on NLRP1 and NLRP3 inflammasomes activation in peripheral blood monocytes. Twenty pre-eclamptic women, 20 normotensive pregnant women (NT) and 20 non-pregnant women (NP) were studied. Enzyme immunoassay was employed for the determination of HA, Hsp70 and High mobility group Box 1 (HMGB1) in plasma, as well as for the detection of Interleukin-1β (IL-1β), IL-18 and tumor necrosis factor alpha (TNF-α) in the supernatant of monocytes cultured with or without HA and Hsp70. The inflammasomes induction was evaluated by the quantification of mRNA for NLRP1, NLRP3, caspase-1, IL-1β, IL-18, HMGB1 and TNF-α by qPCR in monocyte culture. The results showed significantly higher plasma levels of HA, Hsp70 and HMGB1 in pre-eclamptic women than in NT and NP women. Monocytes from women with PE showed endogenous activation of NLRP1 and NLRP3 inflammasomes, and expressed high amounts of IL-1β, IL-18, HMGB1 and TNF-α. The stimulation of monocytes with HA increased the gene expression of NLRP1, NLRP3, caspase-1, TNF-α, IL-1β, HMGB1 and IL-18 and the production of IL-1β in pre-eclamptic women. Monocytes cultured with Hsp70 produced elevated levels of IL-1β and TNF-α through a mechanism independent of inflammasomes activation. These results suggest the participation of these DAMPs in the systemic inflammatory response that is characteristic of PE.

Nanoencapsulation Improves Scavenging Capacity and Decreases Cytotoxicity of Silibinin and Pomegranate Oil Association

Silibinin (SB) and pomegranate oil (PO) present therapeutic potential due to antioxidant activity, but the biological performance of both bioactives is limited by their low aqueous solubility. To overcome this issue, the aim of the present investigation was to develop nanocapsule suspensions with PO as oil core for SB encapsulation, as well as assess their toxicity in vitro and radical scavenging activity. The nanocapsule suspensions were prepared by interfacial deposition of preformed polymer method. SB-loaded PO-based nanocapsules (SBNC) showed an average diameter of 157 ± 3 nm, homogenous size distribution, zeta potential of -14.1 ± 1.7 mV, pH of 5.6 ± 0.4 and SB content close to 100%. Similar results were obtained for the unloaded formulation (PONC). The nanocapsules controlled SB release at least 10 times as compared with free SB in methanolic solution. The SBNC scavenging capacity in vitro was statistically higher than free SB (p < 0.05). Cell viability in monocytes and lymphocytes was kept around 100% in the treatments with SBNC and PONC, while the SB and the PO caused a decrease around 30% at 50 μM (SB) and 724 μg/mL (PO). Protein carbonyls and DNA damage were minimized by SB and PO nanoencapsulation. Lipid peroxidation occurred in nanocapsule treatments regardless of the SB presence, which may be attributed to PO acting as substrate in reaction. The free compounds also caused lipid peroxidation. The results show that SBNC and PONC presented adequate physicochemical characteristics and low toxicity against human blood cells. Thereby, this novel nanocarrier may be a promising formulation for therapeutic applications.

Increased expression of NLRP3 inflammasome in placentas from pregnant women with severe preeclampsia

Preeclampsia is a pregnancy disorder characterized by imbalance between pro- and anti-inflammatory cytokines associated with high plasma levels of uric acid and Interleukin-1 beta (IL-1β). The inflammasome is a protein complex that mediates innate immune responses via caspase-1 activation promoting secretion of IL-1β and IL-18 in their active forms, and also release of the high-mobility group box 1 protein (HMGB1). As the placenta seems to play an important role in the pathogenesis of PE, the present study investigated the expression of genes and proteins related to the inflammasome in placentas from pregnant women with severe preeclampsia. Placental tissue was collected from 20 normotensive pregnant women and 20 preeclamptic women, and inflammasome components, NLRP3 (NOD-like receptor family, pyrin domain-containing protein 3), caspase-1, IL-1β and IL-18, as well as tumor necrosis factor-alpha (TNF-α) and HMGB1 were evaluated by immunohistochemistry, enzyme-linked immunosorbent assay (ELISA) and also quantified by reverse transcription-qPCR (RT-qPCR). Compared with normotensive pregnant women, placenta from women with PE showed a significant increase in NLRP3, caspase-1, IL-1β, TNF-α and HMGB1 mRNA. Immunohistochemical staining of NLRP3, caspase-1, IL-1β and TNF-α in placental villi, as well as the levels of caspase-1, IL-1β, TNF-α and HMGB1 in placental homogenate were significantly higher in the preeclamptic group than in the normotensive group. However, mRNA expression of IL-18 and its protein concentrations were lower in placentas from preeclamptic women. The results suggest that placentas from pregnant women with preeclampsia show higher expression of NLRP3 inflammasome, which may be involved in the exaggerated inflammatory state in preeclampsia.

Association between cytokine profile and transcription factors produced by T-cell subsets in early- and late-onset pre-eclampsia

Pre-eclampsia (PE) is an obstetric pathology characterized by abnormal activation of the innate and adaptive immune systems dependent on the imbalance of T helper subsets. The present study aimed to evaluate the gene and protein expression of T helper type 1 (Th1)/Th2/Th17/regulatory T (Treg) cell transcription factors in peripheral blood lymphocytes from pregnant women with PE employing quantitative RT-PCR and flow cytometry techniques, as well as the cytokine profile produced by these CD4+ T-cell subsets in the plasma of pregnant women with PE, classified as early-onset PE (n = 20), late-onset PE (n = 20) and normotensive pregnant women (n = 20). Results showed a higher percentage of CD4+ T cells expressing the RORc transcription factor (Th17) and a lower percentage of cells expressing FoxP3 (Treg) in women with early-onset PE compared with late-onset PE and normotensive groups. A lower gene expression of GATA-3 transcription factor was detected in cells of women with early-onset PE compared with the late-onset PE group. Endogenous plasma levels of interleukin-6 (IL-6), IL-17 and tumour necrosis factor-α were significantly higher in the early-onset PE group than in the late-onset PE and normotensive groups, whereas IL-4 (Th2 profile) and IL-22 (Th17 profile), were not significantly different between the studied groups. The endogenous levels of transforming growth factor-β and IL-10 were significantly lower in the pre-eclamptic than in the normotensive groups of the same gestational age, with a significant difference between early- and late-onset PE. The results show that in women with PE there is an imbalance between inflammatory and anti-inflammatory profiles in CD4+ T-cell subsets, with polarization to Th17 profiles in the early-onset PE, considered as the severe form of PE.

Therapeutic effects of silibinin on LPS-induced acute lung injury by inhibiting NLRP3 and NF-κB signaling pathways

Silibinin, a natural product extracted from Silybum marianum (milk thistle), has been reported to have anti-inflammatory effect. The aim of this study was to explore the therapeutic effects and potential mechanisms of silibinin on lipopolysaccharide (LPS)-stimulated inflammatory responses in acute lung injury (ALI). Male BALB/c mice were conditioned with silibinin 1 h after intranasal instillation of LPS. After 12 h, the myeloperoxidase (MPO) level in lung tissues, the wet/dry (W/D) ratio, inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), and histopathological examination of lung were detected. Our results showed that silibinin inhibited LPS-induced histopathological changes and MPO activity, as well as the wet/dry (W/D) ratio in the lung tissues. Furthermore, silibinin significantly inhibited LPS-induced inflammatory cytokines production in the BALF. In addition, silibinin suppressed LPS-induced NF-κB activation and the expression of NLRP3 inflammasome. These results indicate that silibinin exerts its anti-inflammatory effect by inhibiting NF-κB and NLRP3 signaling pathways.

Silibinin-mediated metabolic reprogramming attenuates pancreatic cancer-induced cachexia and tumor growth

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the US. Cancer-associated cachexia is present in up to 80% of PDAC patients and is associated with aggressive disease and poor prognosis. In the present studies we evaluated an anti-cancer natural product silibinin for its effectiveness in targeting pancreatic cancer aggressiveness and the cachectic properties of pancreatic cancer cells and tumors. Our results demonstrate that silibinin inhibits pancreatic cancer cell growth in a dose-dependent manner and reduces glycolytic activity of cancer cells. Our LC-MS/MS based metabolomics data demonstrates that silibinin treatment induces global metabolic reprogramming in pancreatic cancer cells. Silibinin treatment diminishes c-MYC expression, a key regulator of cancer metabolism. Furthermore, we observed reduced STAT3 signaling in silibinin-treated cancer cells. Overexpression of constitutively active STAT3 was sufficient to substantially revert the silibinin-induced downregulation of c-MYC and the metabolic phenotype. Our in vivo investigations demonstrate that silibinin reduces tumor growth and proliferation in an orthotopic mouse model of pancreatic cancer and prevents the loss of body weight and muscle. It also improves physical activity including grip strength and latency to fall in tumor-bearing mice. In conclusion, silibinin-induced metabolic reprogramming diminishes cell growth and cachectic properties of pancreatic cancer cells and animal models.

Association between Placental Lesions, Cytokines and Angiogenic Factors in Pregnant Women with Preeclampsia

Preeclampsia (PE) is considered the leading cause of maternal and perinatal morbidity and mortality. The placenta seems to play an essential role in this disease, probably due to factors involved in its formation and development. The present study aimed to investigate the association between placental lesions, cytokines and angiogenic factors in pregnant women with preeclampsia (PE). We evaluated 20 normotensive pregnant women, 40 with early-onset PE and 80 with late-onset PE. Placental samples were analyzed for histopathology, immunohistochemistry and determination of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-10 (IL-10), transforming growth factor-beta 1 (TGF-β₁), tumor necrosis factor-alpha (TNF-α), placental growth factor (PlGF), vascular endothelial growth factor (VEGF), fms-like tyrosine-kinase-1 (Flt-1) and endoglin (Eng) levels. Higher percentages of increased syncytial knots and increased perivillous fibrin deposits, and greater levels of TNF-α, TGF-β1and Flt-1 were detected in placentas from early-onset PE. Levels of IL-10, VEGF and PlGF were decreased in PE versus normotensive placentas. Both the TNF-α/IL-10 and sFlt-1/PlGF ratios were higher in placental homogenate of early-onset PE than late-onset PE and control groups. The more severe lesions and the imbalance between TNF-α/IL-10 and PlGF/sFlt-1 in placentas from early-onset PE allows differentiation of early and late-onset PE and suggests higher placental impairment in early-onset PE.

Stimulatory Effects of Coumestrol on Embryonic and Fetal Development Through AKT and ERK1/2 MAPK Signal Transduction

Successful establishment of pregnancy is required for fetal-maternal interactions regulating implantation, embryonic development and placentation. A uterine environment with insufficient growth factors and nutrients increases the incidence of intrauterine growth restriction (IUGR) leading to an impaired uterine environment. In the present study, we demonstrated the effects of the phytoestrogen coumestrol on conceptus development in the pig that is regarded as an excellent biomedical animal model for research on IUGR. Results of this study indicated that coumestrol induced migration of porcine trophectoderm (pTr) cells in a concentration-dependent manner. In response to coumestrol, the phosphorylation of AKT, P70S6K, S6, ERK1/2 MAPK, and P90RSK proteins were activated in pTr cells and ERK1/2 MAPK and P90RSK phosphorylation was prolonged for a longer period than for the other proteins. To identify the signal transduction pathway induced by coumestrol, pharmacological inhibitors U0126 (an ERK1/2 inhibitor) and LY294002 (a PI3K inhibitor) were used to pretreat pTr cells. The results showed that coumestrol-induced phosphorylation of ERK1/2 MAPK and P90RSK was blocked by U0126. In addition, the increased phosphorylation in response to coumestrol was completely inhibited following pre-treatment incubation of pTr cells in the presence of LY294002 and U0126. Furthermore, these two inhibitors suppressed the ability of coumestrol to induce migration of pTr cells. Collectively, these findings suggest that coumestrol affects embryonic development through activation of the PI3K/AKT and ERK1/2 MAPK cell signal transduction pathways and improvement in the uterine environment through coumestrol supplementation may provide beneficial effects of enhancing embryonic and fetal survival and development. J. Cell. Physiol. 231: 2733-2740, 2016. © 2016 Wiley Periodicals, Inc.

Endogenous and Uric Acid-Induced Activation of NLRP3 Inflammasome in Pregnant Women with Preeclampsia

Preeclampsia (PE) is a specific syndrome of pregnancy, characterized by hypertension and proteinuria. This pathology is associated with hyperuricemia and elevated serum levels of inflammatory cytokines. Uric acid crystals may activate an intracellular complex called inflammasome, which is important for processing and release of inflammatory cytokines. This study investigated the state of monocyte activation, both endogenous and stimulated with monosodium urate (MSU), by gene expression of NLRP1 and NLRP3 receptors as well as their association with inflammatory cytokines expression. Monocytes were obtained from peripheral blood of 23 preeclamptic pregnant women, 23 normotensive pregnant women (NT) and 23 healthy non-pregnant women (NP). Inflammasome activation was evaluated by the gene expression of NLRP1, NLRP3, caspase-1, IL-1β, IL-18 and TNF-α by RT-qPCR in unstimulated monocytes (endogenous expression), or after cell stimulation with MSU (stimulated expression). The concentration of cytokines was assessed by ELISA. In preeclamptic pregnant women, gene expression of NLRP1, NLRP3, caspase-1, IL-1β and TNF-α by monocytes stimulated or not with MSU was significantly higher than in NT and NP groups. Stimulation of monocytes from preeclamptic and non-pregnant women with MSU induced increased gene expression of NLRP3, caspase-1 and TNF-α in relation to the endogenous expression in these groups, while this was not observed in the NT group. The cytokine determination showed that monocytes from women with PE produced higher endogenous levels of IL-1β, IL-18 and TNF-α compared to the other groups, while the stimulus with MSU led to higher production of these cytokines in preeclamptic group than in the NT group. In conclusion, the results showed increased basal gene expression of NLRP1 and NLRP3 receptors in monocytes from PE group. These cells stimulation with MSU demonstrates that uric acid plays a role in NLRP3 inflammasome activation, suggesting the participation of this inflammatory complex in the pathogenesis of preeclampsia.

Silymarin Inhibits Morphological Changes in LPS-Stimulated Macrophages by Blocking NF-κB Pathway

The present study showed that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibited lipopolysaccharide (LPS)-induced morphological changes in the mouse RAW264.7 macrophage cell line. We also showed that silymarin inhibited the nuclear translocation and transactivation activities of nuclear factor-kappa B (NF-κB), which is important for macrophage activation-associated changes in cell morphology and gene expression of inflammatory cytokines. BAY-11-7085, an NF-κB inhibitor, abrogated LPS-induced morphological changes and NO production, similar to silymarin. Treatment of RAW264.7 cells with silymarin also inhibited LPS-stimulated activation of mitogen-activated protein kinases (MAPKs). Collectively, these experiments demonstrated that silymarin inhibited LPS-induced morphological changes in the RAW264.7 mouse macrophage cell line. Our findings indicated that the most likely mechanism underlying this biological effect involved inhibition of the MAPK pathway and NF-κB activity. Inhibition of these activities by silymarin is a potentially useful strategy for the treatment of inflammation because of the critical roles played by MAPK and NF-κB in mediating inflammatory responses in macrophages.

Silymarin as a Natural Antioxidant: An Overview of the Current Evidence and Perspectives

Silymarin (SM), an extract from the Silybum marianum (milk thistle) plant containing various flavonolignans (with silybin being the major one), has received a tremendous amount of attention over the last decade as a herbal remedy for liver treatment. In many cases, the antioxidant properties of SM are considered to be responsible for its protective actions. Possible antioxidant mechanisms of SM are evaluated in this review. (1) Direct scavenging free radicals and chelating free Fe and Cu are mainly effective in the gut. (2) Preventing free radical formation by inhibiting specific ROS-producing enzymes, or improving an integrity of mitochondria in stress conditions, are of great importance. (3) Maintaining an optimal redox balance in the cell by activating a range of antioxidant enzymes and non-enzymatic antioxidants, mainly via Nrf2 activation is probably the main driving force of antioxidant (AO)  action of SM. (4) Decreasing inflammatory responses by inhibiting NF-κB pathways is an emerging mechanism of SM protective effects in liver toxicity and various liver diseases. (5) Activating vitagenes, responsible for synthesis of protective molecules, including heat shock proteins (HSPs), thioredoxin and sirtuins and providing additional protection in stress conditions deserves more attention. (6) Affecting the microenvironment of the gut, including SM-bacteria interactions, awaits future investigations. (7) In animal nutrition and disease prevention strategy, SM alone, or in combination with other hepatho-active compounds (carnitine, betaine, vitamin B₁₂, etc.), might have similar hepatoprotective effects as described in human nutrition.

Silymarin Inhibits Cytokine-Stimulated Pancreatic Beta Cells by Blocking the ERK1/2 Pathway

We show that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibits cytokine mixture (CM: TNF-α, IFN-γ, and IL-1β)-induced production of nitric oxide (NO) in the pancreatic beta cell line MIN6N8a. Immunostaining and Western blot analysis showed that silymarin inhibits iNOS gene expression. RT-PCR showed that silymarin inhibits iNOS gene expression in a dose-dependent manner. We also showed that silymarin inhibits extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) phosphorylation. A MEK1 inhibitor abrogated CM-induced nitrite production, similar to silymarin. Treatment of MIN6N8a cells with silymarin also inhibited CM-stimulated activation of NF-κB, which is important for iNOS transcription. Collectively, we demonstrate that silymarin inhibits NO production in pancreatic beta cells, and silymarin may represent a useful anti-diabetic agent.

Monocytes from pregnant women with pre-eclampsia are polarized to a M1 phenotype

PROBLEM

This study evaluated whether the monocyte inflammatory state in pre-eclampsia (PE) might be associated with polarization to either M1 classically or M2 alternatively activated monocyte subsets.

METHOD OF STUDY

Eighty-five women with (PE) and 52 normotensive (NT) pregnant women matched for gestational age were included. Expression of surface receptors characteristic of M1, such as Toll-like receptor (TLR)2, TLR4, and CD64, or M2, such as CD163 and CD206 monocyte subsets were evaluated in peripheral blood monocytes by flow cytometry. Tumour necrosis factor-alpha (TNF-α), interleukin-(IL)-12p40, IL-12p70, and IL-10 were evaluated in the supernatant of monocyte cultures by ELISA.

RESULTS

Expression of TLR4 and CD64 by monocytes from pre-eclamptic women was significantly higher, while the expression of CD163 and CD206 expression was significantly lower compared with NT pregnant women. Endogenous production of TNF-α, IL-12p40, and IL-12p70 by monocytes was increased, while synthesis of IL-10 was lower in women with PE than in NT pregnant women.

CONCLUSIONS

Monocytes from women with PE are classically activated, producing higher levels of pro-inflammatory cytokines, and express surface receptors characteristic of the M1 subset. These results provide evidence that the systemic inflammatory environment in PE may differentiate and polarize these cells to the M1 phenotype.

Effect of silibinin in reducing inflammatory pathways in in vitro and in vivo models of infection-induced preterm birth

Infection-induced preterm birth is the largest cause of infant death and of neurological disabilities in survivors. Silibinin, from milk thistle, exerts potent anti-inflammatory activities in non-gestational tissues. The aims of this study were to determine the effect of silibinin on pro-inflammatory mediators in (i) human fetal membranes and myometrium treated with bacterial endotoxin lipopolysaccharide (LPS) or the pro-inflammatory cytokine IL-1β, and (ii) in preterm fetal membranes with active infection. The effect of silibinin on infection induced inflammation and brain injury in pregnant mice was also assessed. Fetal membranes and myometrium (tissue explants and primary cells) were treated with 200 μM silibinin in the presence or absence of 10 μg/ml LPS or 1 ng/ml IL-1β. C57BL/6 mice were injected with 70 mg/kg silibinin with or without 50 μg LPS on embryonic day 16. Fetal brains were collected after 6 h. In human fetal membranes, silibinin significantly decreased LPS-stimulated expression of IL-6 and IL-8, COX-2, and prostaglandins PGE2 and PGF2α. In primary amnion and myometrial cells, silibinin also decreased IL-1β-induced MMP-9 expression. Preterm fetal membranes with active infection treated with silibinin showed a decrease in IL-6, IL-8 and MMP-9 expression. Fetal brains from mice treated with silibinin showed a significant decrease in LPS-induced IL-8 and ninjurin, a marker of brain injury. Our study demonstrates that silibinin can reduce infection and inflammation-induced pro-labour mediators in human fetal membranes and myometrium. Excitingly, the in vivo results indicate a protective effect of silibinin on infection-induced brain injury in a mouse model of preterm birth.

Silibinin Inhibits LPS-Induced Macrophage Activation by Blocking p38 MAPK in RAW 264.7 Cells

We demonstrate herein that silibinin, a polyphenolic flavonoid compound isolated from milk thistle (Silybum marianum), inhibits LPS-induced activation of macrophages and production of nitric oxide (NO) in RAW 264.7 cells. Western blot analysis showed silibinin inhibits iNOS gene expression. RT-PCR showed that silibinin inhibits iNOS, TNF-α, and IL1β. We also showed that silibinin strongly inhibits p38 MAPK phosphorylation, whereas the ERK1/2 and JNK pathways are not inhibited. The p38 MAPK inhibitor abrogated the LPS-induced nitrite production, whereas the MEK-1 inhibitor did not affect the nitrite production. A molecular modeling study proposed a binding pose for silibinin targeting the ATP binding site of p38 MAPK (1OUK). Collectively, this series of experiments indicates that silibinin inhibits macrophage activation by blocking p38 MAPK signaling.

High levels of heat shock protein 70 are associated with pro-inflammatory cytokines and may differentiate early- from late-onset preeclampsia

Preeclampsia (PE), a specific syndrome of pregnancy, can be classified into early and late onset, depending on whether clinical manifestations occur before or after 34 weeks' gestation. We determined whether plasma concentrations of Hsp60 and Hsp70 were related to circulating cytokine levels, as well as kidney and liver functions, in early- and late-onset PE. Two hundred and thirty-seven preeclamptic women (95 with early- and 142 with late-onset PE) were evaluated. Plasma levels of Hsp60, Hsp70, and their specific antibodies, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1, IL-10, IL-12, and soluble TNF-α-receptor I (sTNFRI) concentrations, were determined by enzyme-linked immunosorbent assay (ELISA). Concentrations of Hsp70, TNF-α, IL-1β, IL-12, and sTNFRI were significantly elevated in patients with early-onset PE compared with women with late-onset PE; IL-10 levels were significantly lower in the early-onset PE group. Concentrations of urea, uric acid, proteinuria, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and lactate dehydrogenase (LDH) were also significantly higher in early-onset PE. The percentage of infants with intrauterine growth restriction was also significantly higher in women with early-onset PE. There were positive correlations between Hsp70 levels and TNF-α, TNFRI, IL-1β, IL-12, GOT, GPT, LDH, and uric acid concentrations in early-onset PE group. Thus, early-onset PE was associated with greater maternal and fetal impairment. There are differences in pathophysiology between early- and late-onset PE, highlighting by the difference in Hsp70 levels.